There have existed various kinds of elastic raw materials processible to any shape in the past.
Dried powder products, in which ligneous fine powder is blended with sticky substances, are commercially available from SO Co. [1-21-23-201, Ichikawa, Ichikawa-Shi, Chiba-Ken] under the trade name of “Ki no Nendo” (clay of wood). This powder becomes pasty and clayey, after being kneaded with added water and allowed to stand for about one hour. When the molded product is left to stand overnight and then dried, this product solidifies to a certain hardness such as a wood chip. Thus, it is difficult to mold the solidified substance into an intended shape. The solidified substance is breakable if deformation appears therein or impact is given thereto. Further, this substance is deformable when the temperature is increased at a time of drying.
Clay, which is made of soil and commonly used in ceramic arts or the like, is freely molded, however, it takes several days to be dried and solidified. The solidified substance after being dried cannot be molded, so that this substance may be broken due to deformation or impact. This substance also deforms when the temperature is increased at a time of drying. Further, burning of this substance for the purpose of obtaining an enhanced strength may leads to breaking thereof.
Although oil clay used for common handiwork is freely moldable, the oil clay is never dried and solidified, so that this clay remains soft. Thus, it is difficult for the finished product to keep its finished shape, since the molded substance is deformable due to its own weight and is also easily deformable by an external force exerted thereon. Various kinds of paper clay used for common handiwork are freely moldable, but it takes several days until the paper clay is dried and solidified.
It is necessary to pay attention so as to keep the finished shape until the substance will be completely solidified, since the substance is deformable at a time of drying due to its own weight and is also easily deformable by an external force exerted thereon. The solidified substance after being dried cannot easily be molded, so that this substance may be broken due to its deformation or impact.
Although a technique for mixing a synthetic resin with wood chips or small pieces of industrial wastes and then producing a plate or the like with a hot forming machine has been developed by DAIWA HOUSE INDUSTRY Co., Ltd., this technique cannot be applied to a process at normal temperatures. In addition, it is hard to further shape the molded product because of its robustness.